/*
 * ESPRESSIF MIT License
 *
 * Copyright (c) 2018 <ESPRESSIF SYSTEMS (SHANGHAI) PTE LTD>
 *
 * Permission is hereby granted for use on all ESPRESSIF SYSTEMS products, in which case,
 * it is free of charge, to any person obtaining a copy of this software and associated
 * documentation files (the "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the Software is furnished
 * to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all copies or
 * substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */

#ifndef _AUDIO_ELEMENT_H_
#define _AUDIO_ELEMENT_H_

#include "freertos/FreeRTOS.h"

#include "rom/queue.h"
#include "esp_err.h"
#include "audio_event_iface.h"
#include "ringbuf.h"
#include "audio_common.h"

#ifdef __cplusplus
extern "C" {
#endif

typedef enum {
    AEL_IO_OK           = ESP_OK,
    AEL_IO_FAIL         = ESP_FAIL,
    AEL_IO_DONE         = -2,
    AEL_IO_ABORT        = -3,
    AEL_IO_TIMEOUT      = -4,
    AEL_PROCESS_FAIL    = -5,
} audio_element_err_t;

/**
 * @brief Audio element state
 */
typedef enum {
    AEL_STATE_NONE = 0,
    AEL_STATE_INIT,
    AEL_STATE_RUNNING,
    AEL_STATE_PAUSED,
    AEL_STATE_STOPPED,
    AEL_STATE_FINISHED,
    AEL_STATE_ERROR
} audio_element_state_t;

/**
 * Audio element action command, process on dispatcher
 */
typedef enum {
    AEL_MSG_CMD_NONE                = 0,
    AEL_MSG_CMD_ERROR               = 1,
    AEL_MSG_CMD_FINISH              = 2,
    AEL_MSG_CMD_STOP                = 3,
    AEL_MSG_CMD_PAUSE               = 4,
    AEL_MSG_CMD_RESUME              = 5,
    AEL_MSG_CMD_DESTROY             = 6,
    // AEL_MSG_CMD_CHANGE_STATE        = 7,
    AEL_MSG_CMD_REPORT_STATUS       = 8,
    AEL_MSG_CMD_REPORT_MUSIC_INFO   = 9,
    AEL_MSG_CMD_REPORT_CODEC_FMT    = 10,
} audio_element_msg_cmd_t;

/**
 * Audio element status report
 */
typedef enum {
    AEL_STATUS_NONE                     = 0,
    AEL_STATUS_ERROR_OPEN               = 1,
    AEL_STATUS_ERROR_INPUT              = 2,
    AEL_STATUS_ERROR_PROCESS            = 3,
    AEL_STATUS_ERROR_OUTPUT             = 4,
    AEL_STATUS_ERROR_CLOSE              = 5,
    AEL_STATUS_ERROR_TIMEOUT            = 6,
    AEL_STATUS_ERROR_UNKNOWN            = 7,
    AEL_STATUS_INPUT_DONE               = 8,
    AEL_STATUS_INPUT_BUFFERING          = 9,
    AEL_STATUS_OUTPUT_DONE              = 10,
    AEL_STATUS_OUTPUT_BUFFERING         = 11,
    AEL_STATUS_STATE_RUNNING            = 12,
    AEL_STATUS_STATE_PAUSED             = 13,
    AEL_STATUS_STATE_STOPPED            = 14,
    AEL_STATUS_MOUNTED                  = 15,
    AEL_STATUS_UNMOUNTED                = 16,
} audio_element_status_t;

typedef struct audio_element *audio_element_handle_t;

/**
 * @brief Audio Element user reserved data
 */
typedef struct {
    int user_data_0;     /*!< user data 0 */
    int user_data_1;     /*!< user data 1 */
} audio_element_reserve_data_t;

/**
 * @brief Audio Element informations
 */
typedef struct {
    int sample_rates;       /*!< Sample rates in Hz */
    int channels;           /*!< Number of audio channel, mono is 1, stereo is 2 */
    int bits;               /*!< Bit wide (8, 16, 24, 32 bits) */
    int volume;             /*!< Volume in percent */
    bool mute;              /*!< Mute */
    int64_t byte_pos;       /*!< The current position (in bytes) being processed for an element */
    int64_t total_bytes;    /*!< The total bytes for an element */
    char *uri;              /*!< URI (optional) */
    audio_codec_t codec_fmt;/*!< Music format (optional) */
    audio_element_reserve_data_t reserve_data;/*!< This value is reserved for user use */
} audio_element_info_t;

#define AUDIO_ELEMENT_INFO_DEFAULT()    {   \
    .sample_rates = 44100,                  \
    .channels = 2,                          \
    .bits = 16,                             \
    .uri = NULL,                            \
}

typedef esp_err_t (*io_func)(audio_element_handle_t self);
typedef audio_element_err_t (*process_func)(audio_element_handle_t self, char *el_buffer, int el_buf_len);
typedef audio_element_err_t (*stream_func)(audio_element_handle_t self, char *buffer, int len, TickType_t ticks_to_wait,
        void *context);

/**
 * @brief Audio Element configurations
 *        Each Element at startup will be a self-running task.
 *        These tasks will execute the callback open -> [loop: read -> process -> write] -> close
 *        These callback functions are provided by the user corresponding to this configuration.
 *
 */
typedef struct {
    io_func     open;       /*!< Open callback function */
    io_func     seek;       /*!< Seek callback function */
    process_func process;   /*!< Process callback function */
    io_func     close;      /*!< Close callback function */
    io_func     destroy;    /*!< Destroy callback function */
    stream_func read;       /*!< Read callback function */
    stream_func write;      /*!< Write callback function */
    int         buffer_len; /*!< Buffer length use for an Element */
    int         task_stack; /*!< Element task stack */
    int         task_prio;  /*!< Element task priority (based on freeRTOS priority) */
    int         task_core;  /*!< Element task running in core (0 or 1) */
    int         out_rb_size;/*!< Output ringbuffer size */
    void        *data;      /*!< User context */
    char        *tag;       /*!< Element tag */
} audio_element_cfg_t;

#define DEFAULT_ELEMENT_RINGBUF_SIZE    (8*1024)
#define DEFAULT_ELEMENT_BUFFER_LENGTH   (1024)
#define DEFAULT_ELEMENT_STACK_SIZE      (2*1024)
#define DEFAULT_ELEMENT_TASK_PRIO       (5)
#define DEFAULT_ELEMENT_TASK_CORE       (0)

#define DEFAULT_AUDIO_ELEMENT_CONFIG() {\
    .buffer_len         = DEFAULT_ELEMENT_BUFFER_LENGTH,\
    .task_stack         = DEFAULT_ELEMENT_STACK_SIZE, \
    .task_prio          = DEFAULT_ELEMENT_TASK_PRIO, \
    .task_core          = DEFAULT_ELEMENT_TASK_CORE, \
}

/**
 * @brief      Initialize audio element with config
 *
 * @param      config  The configuration
 *
 * @return
 *     - audio_elemenent handle object
 *     - NULL
 */
audio_element_handle_t audio_element_init(audio_element_cfg_t *config);

/**
 * @brief      Destroy audio element handle object, stop, clear, deletel all
 *
 * @param[in]  el    The audio element handle
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_deinit(audio_element_handle_t el);

/**
 * @brief      Set context data to element handle object, it can be retrieve by getdata
 *
 * @param[in]  el    The audio element handle
 * @param      data  The data pointer
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_setdata(audio_element_handle_t el, void *data);

/**
 * @brief      Get context data from element handle object
 *
 * @param[in]  el    The audio element handle
 *
 * @return     data pointer
 */
void *audio_element_getdata(audio_element_handle_t el);

/**
 * @brief      Set elemenet tag name, or clear if tag = NULL
 *
 * @param[in]  el    The audio element handle
 * @param[in]  tag   The tag name pointer
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_set_tag(audio_element_handle_t el, const char *tag);

/**
 * @brief      Get element tag name
 *
 * @param[in]  el    The audio element handle
 *
 * @return    Element tag name pointer
 */
char *audio_element_get_tag(audio_element_handle_t el);

/**
 * @brief      Set audio element infomation
 *
 * @param[in]  el    The audio element handle
 * @param      info  The information pointer
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_setinfo(audio_element_handle_t el, audio_element_info_t *info);

/**
 * @brief      Get audio element infomation
 *
 * @param[in]  el    The audio element handle
 * @param      info  The information pointer
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_getinfo(audio_element_handle_t el, audio_element_info_t *info);

/**
 * @brief      Set audio element URI
 *
 * @param[in]  el    The audio element handle
 * @param[in]  uri   The uri pointer
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_set_uri(audio_element_handle_t el, const char *uri);

/**
 * @brief      Get audio element URI
 *
 * @param[in]  el    The audio element handle
 *
 * @return     URI pointer
 */
char *audio_element_get_uri(audio_element_handle_t el);

/**
 * @brief      Start Audio Element, with this function, audio_element will start as freeRTOS task,
 *             And put the task into 'PAUSED' state.
 *             Note: Element does not actually start when this function returns
 *
 * @param[in]  el    The audio element handle
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_run(audio_element_handle_t el);

/**
 * @brief      Start Audio Element, with this function, audio_element will start as freeRTOS task,
 *             and put the task into 'PAUSED' state.
 *             Note: Element does not actually start when this function returns
 *
 * @param[in]  el    The audio element handle
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_terminate(audio_element_handle_t el);

/**
 * @brief      Request stop of the Audio Element. After receiving the stop request,
 *             the element will ignore the actions being performed (read/write, wait for the ringbuffer ...)
 *             and close the task, reset the state variables.
 *             Note: this API only sends requests, Element does not actually stop when this function returns
 *
 * @param[in]  el    The audio element handle
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_stop(audio_element_handle_t el);

/**
 * @brief      After the `audio_element_stop` function is called, the Element task will perform some abort procedures.
 *             This function will be blocked until Element Task has done and exit.
 *
 * @param[in]  el    The audio element handle
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_wait_for_stop(audio_element_handle_t el);

/**
 * @brief      Request audio Element enter 'PAUSE' state, in this state, the task will wait for any event
 *
 * @param[in]  el    The audio element handle
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_pause(audio_element_handle_t el);

/**
 * @brief      Request audio Element enter 'RUNNING' state, in this state, the task listens to event and invokes the callback functions.
 *             At the same time it will wait until the size/total_size of the output ringbuffer is greater than or equal to `wait_for_rb_threshold`
 *             If the timeout period has been exceeded and ringbuffer output has not yet reached `wait_for_rb_threshold` then the function will return
 *
 * @param[in]  el                     The audio element handle
 * @param[in]  wait_for_rb_threshold  The wait for rb threshold (0 .. 1)
 * @param[in]  timeout                The timeout
 *
 * @return
  *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_resume(audio_element_handle_t el, float wait_for_rb_threshold, TickType_t timeout);

/**
 * @brief      This function will add a `listener` to listen to all events from audio element `el`
 *             Any event from el->external_event will be send to the `listener`.
 *
 * @param      el           The audio element handle
 * @param      listener     The event will be listen to
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_msg_set_listener(audio_element_handle_t el, audio_event_iface_handle_t listener);

/**
 * @brief      Remove listener out of el, no new events will be sent to the listene
 *
 * @param[in]  el        The audio element handle
 * @param      listener  The listener
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_msg_remove_listener(audio_element_handle_t el, audio_event_iface_handle_t listener);

/**
 * @brief      Set Element input ringbuffer
 *
 * @param[in]  el    The audio element handle
 * @param[in]  rb    The ringbuffer handle
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_set_input_ringbuf(audio_element_handle_t el, ringbuf_handle_t rb);

/**
 * @brief       Get Element input ringbuffer
 *
 * @param[in]  el    The audio element handle
 *
 * @return     ringbuf_handle_t
 */
ringbuf_handle_t audio_element_get_input_ringbuf(audio_element_handle_t el);

/**
 * @brief      Set Element output ringbuffer
 *
 * @param[in]  el    The audio element handle
 * @param[in]  rb    The ringbuffer handle
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_set_output_ringbuf(audio_element_handle_t el, ringbuf_handle_t rb);

/**
 * @brief      Get Element output ringbuffer
 *
 * @param[in]  el    The audio element handle
 *
 * @return      ringbuf_handle_t
 */
ringbuf_handle_t audio_element_get_output_ringbuf(audio_element_handle_t el);

/**
 * @brief      Get current Element state
 *
 * @param[in]  el    The audio element handle
 *
 * @return     audio_element_state_t
 */
audio_element_state_t audio_element_get_state(audio_element_handle_t el);

/**
 * @brief      If the element is requesting data from the input ringbuffer, this function forces it to abort
 *
 * @param[in]  el    The audio element handle
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_abort_input_ringbuf(audio_element_handle_t el);

/**
 * @brief      If the element is waiting to write data to the ringbuffer output, this function forces it to abort
 *
 * @param[in]  el   The audio element handle
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_abort_output_ringbuf(audio_element_handle_t el);

/**
 * @brief      This function will wait until the sizeof the output ringbuffer is greater than or equal to `size_expect`
 *             If the timeout period has been exceeded and ringbuffer output has not yet reached `size_expect`
 *             then the function will return `ESP_FAIL`
 *
 * @param[in]  el           The audio element handle
 * @param[in]  size_expect  The size expect
 * @param[in]  timeout      The timeout
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_wait_for_buffer(audio_element_handle_t el, int size_expect, TickType_t timeout);

/**
 * @brief      Element will sendout event (status) to event by this function
 *
 * @param[in]  el      The audio element handle
 * @param[in]  status  The status
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_report_status(audio_element_handle_t el, audio_element_status_t status);

/**
 * @brief      Element will sendout event (information) to event by this function
 *
 * @param[in]  el    The audio element handle
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_report_info(audio_element_handle_t el);

/**
 * @brief      Element will sendout event (codec format) to event by this function
 *
 * @param[in]  el    The audio element handle
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_report_codec_fmt(audio_element_handle_t el);

/**
 * @brief      Set input read timeout (default is `portMAX_DELAY`)
 *
 * @param[in]  el       The audio element handle
 * @param[in]  timeout  The timeout
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_set_input_timeout(audio_element_handle_t el, TickType_t timeout);

/**
 * @brief      Set output read timeout (default is `portMAX_DELAY`)
 *
 * @param[in]  el       The audio element handle
 * @param[in]  timeout  The timeout
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_set_output_timeout(audio_element_handle_t el, TickType_t timeout);

/**
 * @brief      Reset inputbuffer
 *
 * @param[in]  el    The audio element handle
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_reset_input_ringbuf(audio_element_handle_t el);

/**
 * @brief      Reset outputbuffer
 *
 * @param[in]  el    The audio element handle
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_reset_output_ringbuf(audio_element_handle_t el);

/**
 * @brief      Call this function to provice Element input data.
 *             Depending on setup using ringbuffer or function callback, Element invokes read ringbuffer, or calls read callback funtion
 *
 * @param[in]  el            The audio element handle
 * @param      buffer        The buffer pointer
 * @param[in]  wanted_size  The wanted size
 *
 * @return
 *        - > 0 number of bytes produced
 *        - <=0 audio_element_err_t
 */
audio_element_err_t audio_element_input(audio_element_handle_t el, char *buffer, int wanted_size);

/**
 * @brief      Call this function to sendout Element output data.
 *
 * @param[in]  el          Depending on setup using ringbuffer or function callback, Element will invoke write to ringbuffer, or call write callback funtion
 * @param      buffer      The buffer pointer
 * @param[in]  write_size  The write size
 *
 * @return
 *        - > 0 number of bytes written
 *        - <=0 audio_element_err_t
 */
audio_element_err_t audio_element_output(audio_element_handle_t el, char *buffer, int write_size);

/**
 * @brief     This API allows the application to set a read callback for the first audio_element in the pipeline for
 *            allowing the pipeline to interface with other systems. The callback is invoked every time the audio
 *            element requires data to be processed.
 *
 * @param[in]  el        The audio element handle
 * @param[in]  fn        Callback read function. The callback function should return number of bytes read or -1
 *                       in case of error in reading. Note that the callback function may decide to block and
 *                       that may block the entire pipeline.
 * @param[in]  context   An optional context which will be passed to callback function on every invocation
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_set_read_cb(audio_element_handle_t el, stream_func fn, void *context);

/**
 * @brief     This API allows the application to set a write callback for the last audio_element in the pipeline for
 *            allowing the pipeline to interface with other systems. The callback is invoked every time the audio
 *            element has a processed data that needs to be passed forward.
 *
 * @param[in]  el        The audio element
 * @param[in]  fn        Callback write function. The callback function should return number of bytes written or -1
 *                       in case of error in writing. Note that the callback function may decide to block and
 *                       that may block the entire pipeline.
 * @param[in]  context   An optional context which will be passed to callback function on every invocation
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_set_write_cb(audio_element_handle_t el, stream_func fn, void *context);

/**
 * @brief     Get External queue of Emitter, we can read any event that has been send out of Element from this `QueueHandle_t`
 *
 * @param[in]  el    The audio element handle
 *
 * @return     QueueHandle_t
 */
QueueHandle_t audio_element_get_event_queue(audio_element_handle_t el);

/**
 * @brief     Set inputbuffer and outputbuffer have finished.
 *
 * @param[in]  el    The audio element handle
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_set_ringbuf_done(audio_element_handle_t el);

/**
 * @brief     Enforce 'AEL_STATE_INIT' state.
 *
 * @param[in]  el    The audio element handle
 *
 * @return
 *     - ESP_OK
 *     - ESP_FAIL
 */
esp_err_t audio_element_reset_state(audio_element_handle_t el);

/**
 * @brief      Get Element output ringbuffer size
 *
 * @param[in]  el    The audio element handle
 *
 * @return
 *     - =0: Parameter NULL
 *     - >0: Size of ringbuffer
 */
int audio_element_get_output_ringbuf_size(audio_element_handle_t el);

#ifdef __cplusplus
}
#endif

#endif
